Vibratory Compactor Having Conventional and Oscillatory Vibrating Capability

ABSTRACT

A vibratory compactor is disclosed which may include a chassis, a prime mover supported by the chassis, and at least one roller supporting the chassis. The at least one roller may be adapted to emit both conventional vibrations and oscillatory vibrations.

TECHNICAL FIELD

The present disclosure generally relates to compacting machines and, more particularly, relates to vibratory rollers.

BACKGROUND

Vibratory compactors are well known machines for compacting ground substrates. For example, in road construction, after a layer of asphalt is deposited on a prepared bed of dirt or gravel, a vibratory compactor can be rolled over the pavement to provide a relatively uniform compaction and smooth finish. In addition, prior to laying the pavement, a vibratory compactor can be used to compact the underlying substrate of dirt or gravel. Other uses are certainly possible.

Over time, vibratory compactors have greatly evolved. At the outset, the rollers were simply weighted drums, or drums weighted down by the weight of the machine, which then rotated over the surface to be compacted. Subsequently, it was learned that the compacting of the pavement could be improved by concurrently vibrating the roller while it rotated over the substrate. Even further, the paving industry has evolved so as to provide vibratory rollers which emit either conventional vibrations, or oscillatory vibrations. Typically, a customer would choose between a conventional vibratory drum and an oscillatory drum depending upon the thickness of the material being compacted. For example, for relatively thin lifts of asphalt, oscillatory vibrations are typically used, and for relatively thick lifts, conventional vibrations are typically used.

One example of such technology is set forth in U.S. Pat. No. 6,829,986. With such a compactor, an oscillatory drum is provided at the rear of the machine, and conventional vibratory drum is provided at the front of the machine. While effective for its intended purpose, this necessarily adds to the overall cost of the machine in that complicated machinery, to affect the desired vibrations needs to be provided on two separate drums of the vibratory compactor.

It can therefore be seen that a need exists for a vibratory compactor having conventional and oscillatory vibration capability within a single drum.

SUMMARY OF THE DISCLOSURE

In accordance with one aspect of the disclosure, a vibratory roller assembly is disclosed which may include a drum, a motor operatively associated with the drum, a drive shaft powered by the motor, a solid mass eccentric mounted to a second rotatable shaft within the drum, and an adjustable mass eccentric mounted to a third rotatable shaft within the drum, the second and third shafts being rotationally connected to the drive shaft.

In accordance with another aspect of the disclosure, a vibratory compactor is disclosed that may include a chassis, a prime mover supported by the chassis, and at least one roller supporting the chassis, the at least one roller being adapted to emit conventional vibrations when rotated in a first direction and oscillatory vibrations when rotated in a second direction.

In accordance with a still further aspect of the disclosure, a vibratory roller drum is disclosed which may include a cylinder, a conventional vibrator operatively associated with the cylinder to emit conventional vibrations when rotated in a first direction, and an oscillatory vibrator operatively associated with the cylinder to emit oscillatory vibrations when rotated in a second direction.

These and other aspects and features of the present disclosure will be better understood upon reading the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vibratory compactor constructed in accordance with the teachings of the present disclosure;

FIG. 2 is a sectional view taken through line 2-2 of FIG. 1, and showing the inner mechanics of the vibratory roller assembly of the present disclosure;

FIG. 3 is perspective view of a portion of the vibratory roller assembly showing the solid mass and adjustable mass eccentrics;

FIG. 4 is a schematic illustration of the adjustable mass eccentric spinning in a counterclockwise direction;

FIG. 5 is a schematic illustration of the adjustable mass eccentric of FIG. 4, but spinning in a clockwise direction;

FIG. 6 is an end cross-section of a vibratory drum constructed in accordance with the present disclosure, and in various rotational positions so as to generate conventional vibrations;

FIG. 7 is an end cross-section similar in scope to FIG. 7, but depicting various rotational positions so as to generate oscillatory vibrations; and

FIG. 8 is a flow chart depicting a sample sequence of steps that may be practiced in accordance with the present disclosure.

While the following detailed description will be given with specific reference to certain illustrative embodiments, it is to be understood that the present disclosure is not limited to the embodiments specifically disclosed. Rather, the present disclosure is entitled to coverage exemplified by the appended claims, and equivalents thereof when read in light of the present disclosure.

DETAILED DESCRIPTION

Referring now to the drawings, and with specific reference to FIG. 1, a vibratory compactor constructed in accordance with the present disclosure is generally referred to by reference numeral 20. While the depicted compactor is one employing fore and aft rollers 22, it is to be understood that the teachings of the present disclosure can be used with equal efficacy in conjunction with rollers having only a single roller 22, along with another form of location such as, but not limited to, wheels and the like.

The vibratory compactor 20 is shown to include a chassis 24 supported by the rollers 22, a prime mover 25, and an operator station 26. The prime mover 25 may be any form of power generator such as, but not limited to, diesel engines, Otto cycle engines, natural gas engines, electric motors and the like. As shown, the vibratory compactor 20 is adapted to navigate over ground surface 28, such as but not limited to asphalt, gravel and soil, to compact same.

Turning now to FIG. 2, a vibratory roller assembly 30 forming part of the roller 22 is shown in cross-section. As shown, the vibratory roller assembly 30 may include a drum or cylinder 32, the external surface 34 of which serves as the direct interface with the surface 28 to be compacted. The drum 32 is supported for rotation by way of first and second support arms 36, 38.

With specific reference to the first support arm 36, it mounts a gearbox 40 and a propel motor 42 so as to provide rotation to the drum 32, and thus locomotion to the compactor 20. The gearbox 40 and motor 42 in turn are operatively associated with an first end flange 44 extending radially out from the gearbox 40 to an internal surface 46 of the drum 32. A plurality of elastomeric mounts or iso-mounts 48 may be provided therebetween to provide damping.

At the end opposite to the gearbox 40, a vibratory motor 50 is provided. In addition, a drum support bearing 52 is mounted to the support arm 38 and adjacent another plurality of iso-mounts 54. A second end flange 56 then secures the iso-mounts 54 to the internal surface 46 of the drum 32. The second end flange 56 includes an aperture 58, the importance of which will now be described.

Flanked by the first and second end flanges 44, 56, a center bulkhead 60 spans diametrically across the drum 32. Mounted within the center bulkhead 60 is a central bearing 62, a solid mass eccentric assembly 64, and an adjustable mass eccentric assembly 66. The central bearing 62 rotatably journals a drive shaft 68, which in turn is connected to an input shaft 70 extending from the vibratory motor 50. Thus, rotation of the vibratory motor 50 causes rotation of the input shaft 70, which in turn causes rotation of the drive shaft 68.

As will be noted from both FIG. 2 and FIG. 3, the drive shaft 68 is also connected to first and second sheaves 72, 74. Moreover, a third sheave 76 is rotatably connected to the solid mass cavity 77 forming part of the solid mass eccentric assembly 64, while a fourth sheave 78 is rotatably connected to the adjustable mass cavity 79 forming part of the adjustable mass eccentric assembly 66. A first drive belt 80 is then trained about the first and third sheaves 72, 76, while a second drive belt 82 is trained about the second and fourth sheaves 74, 78. Of course, in alternative embodiments, belt drives need not be used, but could be replaced by, but not limited to, chain drives, direct gear couplings, and the like.

Still referring to FIGS. 2 and 3, the solid mass cavity 77 is shown to include a hollow housing 84, rotatably journaling a solid mass shaft 86. A solid mass eccentric 88, manufactured from a solid block of metal such as steel or iron, is then mounted to the solid mass shaft 86. Accordingly, rotation of the solid mass shaft 86 causes the solid mass eccentric 88 to rotate. Given its off-center orientation relative to the solid mass shaft 86, such rotation causes vibrations to be emitted. Moreover, given the fixed connection of the solid mass cavity 77 to the center bulkhead 60, such vibrations are transmitted through the drum 32, and thus ultimately to the surface 26 being paved or compacted.

Diametrically opposite the solid mass cavity 77, is the adjustable mass cavity 79. As shown best in FIG. 2, the adjustable mass cavity 79 includes a hollow housing 90 which, similar to the solid mass cavity 77, rotatably journals an adjustable mass eccentric drive shaft 92. However, dissimilar to the solid mass cavity 77, a solid mass eccentric 88 is not fixed to the adjustable mass eccentric drive shaft 92, but rather an adjustable mass container 94 is fixed to the adjustable mass eccentric drive shaft 92. Within the adjustable mass container 94, an adjustable mass eccentric 96, such as a volume of metal shot or the like, is provided. However, as will be described in further detail below, the metal shot 96 does not completely fill the container 94. Accordingly, as the drive shaft 92 rotates, the container 94 rotates with the drive shaft 92, and the metal shot 96 moves within the container. Depending upon the direction of rotation then, the vibrations emitted by the vibratory roller assembly 30 can be changed to oscillatory, as opposed to conventional, both of which will now be described in further detail.

Referring now to FIGS. 4 and 5, the adjustable mass cavity 79 is shown in end view such that the shape of the adjustable mass container 94 can be appreciated. As shown, the container 94 is substantially cylindrical in shape, but for a wedge-shaped void 98 created by partitions 100, 102. Accordingly, it can be seen that when the adjustable mass cavity 66 is rotated in a counterclockwise direction as shown in FIG. 4, the metal shot 96 shifts within the adjustable mass container 94 so as to be proximate to the first partition 100. However, when the adjustable mass cavity 66 rotates in the opposite direction, i.e., the clockwise direction of FIG. 5, the metal shot 96 shifts again within the adjustable mass container 94 so as to be proximate the second partition 102.

The significance of this shift and its impact on the ability of the vibratory roller assembly 30 to generate conventional or oscillatory vibrations is best depicted in FIGS. 6 and 7. As used herein, “conventional” vibrations are defined as those occurring at constant or consistent frequency or amplitude, and “oscillatory” vibrations are defined as those occurring at inconsistent frequencies or amplitudes. Starting with FIG. 6, the vibratory roller assembly 30 is shown in end cross-section so that the relative positions of the solid mass eccentric 88 and the adjustable mass eccentric 96 can be understood. In such a configuration, it will be noted that solid mass eccentric 88 and adjustable mass eccentric 96 are rotated in sync or phase as they are always positioned at the same radial disposition relative to their respective drive shafts 86, 92. In other words, when the solid mass eccentric 88 is positioned at twelve o′clock relative to its drive shaft 86, the adjustable mass eccentric 96 is positioned at twelve o'clock relative to its drive shaft 92, as shown in the first block 104 of FIG. 6. Similarly, when the solid mass eccentric 88 is positioned at three o'clock relative to its drive shaft 86, the adjustable mass eccentric 96 is positioned at three o'clock relative to its drive shaft 92 as shown in the third block 108 of FIG. 6. In so doing, the vibratory roller assembly 30 is able to generate conventional vibrations in such a configuration.

However, turning now to FIG. 7, when the vibratory motor 50 is rotated in the opposite direction, the metal shot shifts within the container 94 such that the adjustable mass eccentric 96 is out of sync or phase with the solid mass eccentric 88. In the depicted embodiments, the eccentrics 88, 96 are rotated clockwise to generate the conventional vibrations of FIG. 6, and counterclockwise to generate the oscillatory vibrations of FIG. 7, but it is to be understood that the opposite orientation is possible as well. In addition, in the oscillatory vibration orientation of FIG. 7, the adjustable mass eccentric 96 is shifted so as to be 180° out of phase with the solid mass eccentric 88, but it is to be understood that the degree of phase shift can be anywhere along the 0° to 360° arc. For example, the rotational angle at which the container 94 is fixed to the drive shaft 92 can be tailored to generate the desired degree of phase shift. Alternatively, or in additionally, the volume of shot 96 relative to the container 94 available space can be adjusted to affect phase shift, or the weight of the shot 96 relative to the solid mass eccentric 88 can be adjusted as well.

Finally, so as to enable the operator of the vibratory compactor 20 to choose between conventional vibrations and oscillatory vibrations, an operator interface 136 may be provided in the operation station. Such an operator interface 136 may be so provided with any manner of known input/output device such as but not limited to touchscreens, push buttons, toggle switches and the like. Moreover, a computer processor 138 may work in concert with the operator interface 136 so as to receive signals therefrom, and in turn generate signals for transmission to the vibratory motor to rotate in the clockwise or counterclockwise directions depending on whether conventional or oscillatory vibrations are desired.

INDUSTRIAL APPLICABILITY

From the foregoing, it can be seen that the technology disclosed herein has industrial applicability in a variety of settings such as, but not limited machines used for compacting ground substrates such as pavement, soil, gravel, and the like. For example, using the teachings of the present disclosure, a vibratory compactor can be manufactured that not only compacts asphalt for new road construction, but that generates vibrations so as to more evenly and efficiently do so.

In operation, the vibratory compactor is able to do so using the foregoing structure, but by practicing the following method as well. As depicted in the flowchart of FIG. 8, the method may begin at a step 200 where operation of the vibratory compactor 20 is initiated by an operator. A first decision 202 is then to determine if a thin lift of asphalt is desired. If yes, oscillatory vibrations are to be used as indicated by a step 204. At that point, the vibratory motor 50 is caused to rotate in a first direction as shown in step 206, which in turn causes the metal shot 96 within the adjustable mass cavity 79 to shift so as to rotate out of phase with the solid mass eccentric 88 as indicated in a step 208.

However, if a relatively thick lift of asphalt is desired, conventional vibrations are initiated as indicated by step 210. At that point, the vibratory motor 50 is caused to rotate in a second direction, opposite to the first direction, as shown by step 212. This in turn causes the metal shot 96 to shift so as to rotate in phase with the solid mass eccentric 88 as indicated in a step 214.

After each branch of the decision tree, the system asks if continue compacting is desired as shown at step 216. If yes, the method reverts back to the initial step 200. If not, the vibratory compactor 20 is caused to stop operation as shown by end step 218.

From the foregoing, it can be seen that not only does the vibratory compactor of the present disclosure vibrate the roller while rotating, but is further adapted to generate conventional vibrations, as well as oscillatory vibrations from the same roller. This is a significant improvement over the prior art, which has heretofore had to provide one roller, typically at one of the front or rear of the machine, to generate conventional vibrations, and a second roller, typically at the remainder of the rear and front, to generate oscillating vibrations. By providing a single roller that can generate both types of vibrations, the vibratory compactor of the present disclosure can not only handle thick and thin lifts of asphalt with equal aplomb, but it can do so at greatly reduced cost, and greatly increased reliability, over the prior art as well. 

What is claimed is:
 1. A vibratory roller assembly, comprising: a drum; a motor operatively associated with the drum; a drive shaft powered by the motor; a solid mass eccentric mounted to a second rotatable shaft within the drum; and an adjustable mass eccentric mounted to a third rotatable shaft within the drum, the second and third shafts being rotationally connected to the drive shaft.
 2. The vibratory roller assembly of claim 1, wherein the solid mass eccentric and adjustable mass eccentric are rotated 180 degrees apart relative to the drive shaft.
 3. The vibratory roller assembly of claim 1, wherein the motor drive shaft, second shaft, third shaft solid mass eccentric and adjustable mass eccentric are rotatable in first and second directions.
 4. The vibratory roller assembly of claim 3, wherein the vibratory roller drum produces conventional vibrations when the motor, drive shaft, second shaft, third shaft, solid mass eccentric and adjustable mass eccentric are rotated in the first direction.
 5. The vibratory roller assembly of claim 3, wherein the vibratory roller drum produces oscillatory vibration when the motor, drive shaft, second shaft, third shaft, solid mass eccentric, and adjustable mass eccentric are rotated in the second direction.
 6. The vibratory roller assembly of claim 1, wherein the adjustable mass eccentric includes a volume of metallic shot shiftable within a container housing.
 7. The vibratory roller assembly of claim 1, further including a first sheave mounted to the drive shaft and a first belt connecting the first sheave to the solid mass eccentric.
 8. The vibratory roller assembly of claim 7, further including a second sheave mounted to the drive shaft and a second belt connecting the second sheave to the adjustable mass eccentric.
 9. A vibratory compactor, comprising: a chassis; a prime mover supported by the chassis; and at least one roller supporting the chassis, the at least one roller adapted to emit conventional vibrations when rotated in a first direction and oscillatory vibrations when rotated in a second direction.
 10. The vibratory compactor of claim 9, wherein the at least one roller includes a solid mass eccentric and an adjustable mass eccentric.
 11. The vibratory compactor of claim 9, wherein the at least one roller further includes a motor and a drive shaft operatively associated with the motor, the solid mass eccentric and adjustable mass eccentric being rotatably associated with the drive shaft.
 12. The vibratory compactor of claim 11, wherein the at least one roller emits the conventional vibrations when the motor rotates in a clockwise direction, and emits oscillatory vibrations when the motor rotates in a counterclockwise direction.
 13. The vibratory compactor of claim 11, wherein the first direction is opposite to the second direction.
 14. The vibratory compactor of claim 11, wherein the at least one roller further includes a second shaft, and a third shaft, the second and third shaft being rotated by the drive shaft, the solid mass eccentric being mounted on the second shaft, and the adjustable mass eccentric being mounted on the third shaft.
 15. The vibratory compactor of claim 12, further including a cavity mounted to the third shaft, the cavity being partially filled with metallic shot.
 16. A vibratory roller drum, comprising; a cylinder; a conventional vibrator operatively associated with the cylinder to emit conventional vibrations when rotated in a first direction; and an oscillatory vibrator operatively associated with the cylinder to emit oscillatory vibrations when rotated in a second direction.
 17. The vibratory roller drum of claim 16, wherein the conventional vibrator includes a solid mass eccentric.
 18. The vibratory roller drum of claim 16, when the oscillatory vibrator includes an adjustable mass eccentric.
 19. The vibratory roller drum of claim 16, further including a motor operatively associated with the conventional vibrator and the oscillatory vibrator, the vibratory roller drum emitting conventional vibrations when the motor is rotated in a clockwise direction, the vibratory roller drum emitting oscillatory vibrations when the motor is rotated in a counterclockwise direction.
 20. The vibratory roller drum of claim 19, further including a drive shaft coupled to the motor, the conventional vibrator including a second shaft operatively associated with the motor, the oscillatory vibrator including a third shaft operatively associated with the motor, the solid mass eccentric being mounted on the second shaft, and the adjustable mass eccentric being mounted on the third shaft. 